Protective screen for a timepiece casing

ABSTRACT

An annular protective jacket of hard scratch-resistant material such as tungsten carbide covers and protects the sidewall and front edge of the casing of a wristwatch. The protective jacket is removably secured in place on the casing by a ring of elastomeric material received in mating annular grooves provided respectively in the sidewall of the casing spaced from the front edge and in the inner periphery of the protective jacket. A second elastomeric ring may be provided between the front edge of the casing and an inwardly projecting rim portion of the protective jacket to absorb axial shocks applied to the jacket.

United States Patent Piquerez Feb. 22, 1972 [54] PROTECTIVE SCREEN FOR A 2,582,473 1/1952 Belfert ..58/l05 X TIM EPIECE CASING FOREIGN PATENTS OR APPLICATIONS [72] g g 2854 23,761 6/1902 Switzerland ..58/l05 [22] Filed: Sept. 30, 1969 Primary Examiner-Richard B. Wilkinson Assistant Examiner-George H. Miller, Jr. PP 362,255 Attorney-Robert E. Burns and Emmanuel J. Lobato 52] us. Cl. ..5s/ss R, 5s/s.s c, 58/105 [571 ABSTRACT [51] Int. Cl. ..G04b 37/00 An annular protective jacket of hard scratchqes istant material Field of Search 5, 8 such as tungsten carbide covers and protects the sidewall and 244/4 front edge of the casing of a wristwatch. The protective jacket is removably secured in place on the casing by a ring of [56] R fe Cit d elastomeric material received in mating annular grooves provided respectively in the sidewall of the casing spaced from UNITED STATES PATENTS the front edge and in-the inner periphery of the protective 7 jacket. A second elastomeric ring may be provided between l 13 9 3 the front edge of the casing and an inwardly projecting rim l p'querez l 0 portion of the protective jacket to absorb axial shocks applied 3,512,354 5/1970 Jenny ....58/ R to the acket. 1,199,256 9/1916 Farr ..58/l05 X 1,313,798 8/1919 Devine ..58/ UX 5 Claims, 3 Drawing Figures PAIENTEnrmz I972 3. 643 ,423

SHEET 2 OF 2 FIG.3

PROTECTIVE SCREEN FOR A TIMEPIECE CASING This invention relates to protective covers or jackets for timepiece casings, at least one part of which is in a hard metal or alloy which is difficult to scratch.

There are known watch casings of which at least certain visible parts are constituted by a metallic carbide and preferably tungsten carbide. In known watches these parts in metallic carbides are forced or stuck to the casings, which necessitates that they are provided with extremely precise dimensions.

There are also known watch casings formed from two separable parts such as that described in Swiss Pat. No. 321,952. However, the two parts of such a casing are rigidly assembled and are of easily scratchable materials.

It is an object of the present invention to provide a protective cover or jacket for a watch casing which obviates these drawbacks.

According to the invention there is provided a timepiece casing comprising an annular protective jacket made of a hard and difficult to scratch material, said jacket being removably mounted on an element of said casing by elastic means.

The invention will now be particularly described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a partial cross section of a first embodiment of a protective jacket according to the invention,

FIG. 2 is a variant of this embodiment, and

FIG. 3 is a cross section of a second embodiment.

In FIG. 1 there is shown a watchcase C for a movement M. The case C has a sidewall formed by a middle bezel 1 having a front edge 1b. A crystal or glass G is set in the front of the bezel while a bottom is screwed into the back.

The protective cover screen shown in FIG. 1 comprises, elastically mounted on its middle bezel I, an annular jacket of hard material which is difficult to scratch, for example tungsten carbide. The annular jacket 2 has a skirt portion which covers the sidewall of the casing and an inwardly projecting rim portion 2b which overlies the front edge lb and extends in approximately to the crystal G.

The elastic mounting of the annular jacket 2 is provided by an elastic ring 3, of natural or synthetic rubber or of any other similar elastomeric material, which is mounted in two hollows la, 2a, provided respectively in the middle bezel 1 and in the dome 2.

These two grooves are slightly staggered apart when the jacket is fitted on the middle bezel so that the elastic reaction of the ring 3 provides a pull on the jacket 2 and a pressure on the middle bezel 1.

To facilitate penetration of this elastic ring into the grooves, there is provided, in the jacket 2, a conical part 4 intended to compress the ring 3 housed in hollow la upon putting the jacket in place. A cylindrical part 5 is adjacent this conical part and corresponds to a protrusion 6 of the middle bezel 1 in a manner to allow a gap enabling a certain play between the jacket and the bezel middle.

It is evident that the elastic ring could be replaced by a spring, or a resilient wire or blade.

In the variant shown in FIG. 2, the casing comprises instead of a middle bezel, a bottom bezel 7 on which is mounted, as previously described, the annular cover or jacket 2 of hard material. In this variant is shown a possible provision of a recess 8 in the jacket 2 receiving a crown 9 and a pendant 10.

Such a recess has also been indicated, in dashed-dotted lines, in FIG. I.

In the second embodiment, shown in FIG. 3, between the upper part of the middle bezel l and the shoulder 2b of the jacket 2 of hard material there is interpositioned a shock absorbing elastomeric ring 11 intended to absorb axial shocks. This ring 11 can, as shown in the drawing, be of circular section and-be lodged in a hollow of the middle bezel. It can alternatively have a rectangular or square section able possibly to extend along the entire length of the shoulder 2b. This shock absorbing ring 11 is preferably of natural or synthetic rubber.

As a variant of this embodiment, the bottom 15, as described for FIG. 2, can be in a single piece with the middle bezel.

The passage for the winding stem is provided, in the first embodiment, in U-shape. As shown in FIG. 3, for the passage of this winding stem there can be provided an opening 12 in the jacket 2 in line with a hole 13 provided in the middle bezel l and adapted to receive a winding crown and pendant. This construction ensures the continuity of the lower edge of the jacket which is thus less fragile.

The difficult-to-scratch hard material of which the jacket forming the protecting cover 2 is constituted can, of course, be a metallic carbide, such as tungsten carbide. The advantage of a protecting cover elastically mounted on a part of the watch casing is that it does not necessitate accurate dimensioning of the cover, the material of which is difficult to machine in the sintered state. Additionally, mounting of the cover is facilitated.

Other materials, such as ceramics, based on metallic oxides such as alumina, superficially hardened or treated stainless steel etc. can be used for the manufacture of such a cover.

Another advantage is that in case of shock, the elastic mounting protects on the one hand the cover, often fragile, and on the other hand the other parts of the watch, in particular the movement and the glass. Additionally, an infinite number of watch cases of different aesthetic aspects can be constructed simply by changing the shape of the cover, the other elements being standardised.

This protecting cover can possibly be provided with means for attaching a bracelet, such as holes for a bar, for example.

This cover can, as previewed in FIGS. 1 and 2, be removably mounted in a manner to be able to be disassembled by the user, who could thus possibly change one cover for another. Alternatively, the removable mounting could be made more resistant in a manner so as not to enable dismantling by the user, but solely by means of a tool, such as a staying tool, possessed only by a person skilled in the art.

Obviously for the embodiment of FIG. 3, the dismantling can only be carried out by a worker skilled in the art who must open the bottom to remove the crown and the winding stem.

Such a cover can also entirely cover the winding crown which thus becomes invisible when the watch is worn.

Such a mounting is particularly interesting if it is wished, for example upon the driving of an automobile, to wear the watch with the 12-6 hours axis perpendicular to the general axis of the bracelet. The cover can, for this purpose, carry means enabling positioning of the remainder of the watch at different angles. These means could, for example, be provided by several recesses for the crown, defining several angular positions, or by provision of a polygonal casing lodged in a cover provided with a recess of corresponding shape.

Throughout the description the shape of the watch casing has not been mentioned because it is clear that the protecting cover can be provided with a circular recess or with any other shapes: oval, polygonal, in the shape of a television screen and so on, corresponding to the shape of the watch casing to which it is adapted.

What is claimed is:

1. In a wristwatch having a casing housing a watch move ment and having a sidewall with a front edge, the improvement comprising an annular groove extending entirely around said sidewall of said casing and spaced rearwardly from said front edge, an annular protective jacket for protecting said casing, said protective jacket being of hard scratch-resistant material and having a skirt portion covering said sidewall of said casing and an inwardly extending rim portion overlying said front edge, said skirt portion having an annular groove extending around its entire inner periphery and spaced from said rim portion to be disposed in radial alignment with said annular groove, and a ring of elastomeric material surrounding said casing and projecting into said groove in the casing and said groove in said protective jacket to resiliently interconnect said casing and jacket and secure said jacket fixedly on said casing.

2. In a wristwatch having a casing for housing a watch movement as set forth in claim 1 a further improvement in which said casing has a second groove provided in its said front edge portion which is covered by said rim portion of said jacket, said second groove extending entirely around said front edge portion, and a second ring of elastomeric material is disposed in said second casing groove and projects above said front edge, whereby axial shocks applied to said protective jacket are absorbed by said second elastomeric ring.

3. In a wristwatch having a casing for housing a watch movement as set forth in claim 1 said wristwatch having a laterally projecting crown, a further improvement in which said protective jacket is recessed to accommodate said crown in a selected angular position of said jacket on said casing.

4. In a wristwatch having a casing for housing a watch movement as set forth in claim 1 a further improvement in which said protective rim means is composed of a metallic carbide material.

5. In a wristwatch having a casing for housing a watch movement as set forth in claim 1 a further improvement wherein said inner periphery of said skirt portion of said protective jacket, and said protective jacket is received downwardly over said casing, whereby said outwardly inclined inner periphery gradually compresses said first elastomeric ring as said protective jacket is received over said casing. 

1. In a wristwatch having a casing housing a watch movement and having a sidewall with a front edge, the improvement comprising an annular groove extending entirely around said sidewall of said casing and spaced rearwardly from said front edge, an annular protective jacket for protecting said casing, said protective jacket being of hard scratch-resistant material and having a skirt portion covering said sidewall of said casing and an inwardly extending rim portion overlying said front edge, said skirt portion having an annular groove extending around its entire inner periphery and spaced from said rim portion to be disposed in radial alignment with said annular groove, and a ring of elastomeric material surrounding said casing and projecting into said groove in the casing and said groove in said protective jacket to resiliently interconnect said casing and jacket and secure said jacket fixedly on said casing.
 2. In a wristwatch having a casing for housing a watch movement as set forth in claim 1 a further improvement in which said casing has a second groove provided in its said front edge portion which is covered by said rim portion of said jacket, said second groove extending entirely around said front edge portion, and a second ring of elastomeric material is disposed in said second casing groove and projects above said front edge, whereby axial shocks applied to said protective jacket are absorbed by said second elastomeric ring.
 3. In a wristwatch having a casing for housing a watch movement as set forth in claim 1 said wristwatch having a laterally projecting crown, a further improvement in which said protective jacket is recessed to accommodate said crown in a selected angular position of said jacket on said casing.
 4. In a wristwatch having a casing for housing a watch movement as set forth in claim 1 a further improvement in which said protective rim means is composed of a metallic carbide material.
 5. In a wristwatch having a casing for housing a watch movement as set forth in claim 1 a further improvement wherein said inner periphery of said skirt portion of said protective jacket, and said protective jacket is received downwardly over said casing, whereby said outwardly inclined inner periphery gradually compresses said first elastomeric ring as said protective jacket is received over said casing. 